fix(client): swallow synchronous EPIPE from writeAfterFIN (#3282)

[nkaradzhov]

net.Socket.write can throw synchronously with code 'EPIPE' on a half-closed socket, before the 'close' event fires. The throw escaped RedisSocket.write from a setImmediate flush and crashed the process. Preflight writable, wrap the cork/write loop in try/finally so uncork always runs, and narrowly swallow EPIPE — the close handler will reject the pending command via #waitingForReply.

Fixes #3282

Description

Describe your pull request here

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Checklist

• Does npm test pass with this change (including linting)?
• Is the new or changed code fully tested?
• Is a documentation update included (if this change modifies existing APIs, or introduces new ones)?

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Note

Medium Risk
Touches core socket write-path behavior; while narrowly scoped and covered by new tests, it could change how some edge-case disconnect/write failures are handled during reconnects.

Overview
Prevents process crashes when net.Socket.write throws synchronously on half-closed connections by skipping writes when the underlying socket is not writable, wrapping the corked write loop in try/finally to always uncork(), and swallowing only EPIPE while rethrowing other errors.

Adds targeted unit tests that capture the underlying net.Socket to verify the new short-circuit behavior, EPIPE swallowing, and non-EPIPE error propagation.

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